Granted Patent
Utility
US 4,895,619 · App. 07/302,962
Method of delignification of cellulosic fiber material
Inventors:
Bjorn Ahs, Rune Hillstrom
Patented Case
View Patent ↗
Granted: Jan 23, 1990
Filed: Jan 30, 1989
Inventors
Bjorn Ahs
Rune Hillstrom
Assignee (at issue)
Kamyr AB
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.